Semiautomatic grenade launcher



Oct. 8, 1968 s. D. slLsBY 3,404,479

SEMIAUTOMATC GRENADE LAUNCHER med Nov. 15, 1961 5 sheets-sheet 1 Get. 8, 1968 s. D. sxLsBY 3,404,479

SEMIAUTOMATIC GRENADE LAUNCHER Filed Nov. l5, 1961 5 Sheets-Sheet 2 IN VEN TOR.

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5 Sheets-Sheet 3 Oct. 8, 1968 s. D. snLsBY SEMIAUTOMATIC GRENADE LAUNCHER Filed Nov. 15. 1961 Uct. 8, 1968 s. D. slLsBY 3,404,479

SEMIAUTOMATIC GRENADE LAUNCHER Filed NOV. l5, 1951 5 Sheets-511661l 4 INVENTOR.

Wam@ 115i@ Oct 8, w68 s. D. slLsBY 3,404,479

SEMIAUTOMATIC GRENADE LAUNCHER Filed Nov. l5, 1961 5 Sheets-Sheet 5 INVENTOR.

Jiu@ D- 51153237 BY United States Patent O 3,404,479 SEMIAUTOMATIC GRENADE LAUNCHER Stanley D. Silsby, Granby, Mass., assignor to the United States of America as represented by the Secretary of the Army Filed Nov. 15, 1961, Ser. No. 153,259 15 Claims. (Cl. 42-1) The invention described herein may be manufactured and used by or for the Government for governmental purposes without the payment of any royalty thereon.

This inventionY relates to .rifle supported launchers for grenades and more particularly to such launchers which are semiautomatic in operation.

Included in modern ordnance is an ammunition in which a grenade is included in a round having a case and a primer-ignited propellant with low velocity characteristics. It is the principal object of this invention to provide a semiautomatic launcher for such a grenade round using discharge gas pressure for cocking the firing pin and unlocking the reciprocating tiring tube and the frictional force produced by the passage of the discharged grenade down the tiring tube to eject the fired case and load the succeeding round.

It is another object of this invention to provide such a semiautomatic launcher which is simple in construction, positive in operation and is easily manufactured.

The specific nature of the invention as well as other objects and advantages thereof will clearly appear from a description of a preferred embodiment as shown in the accompanying drawings in which:

FIG. 1 is a longitudinally cross-sectioned view of the grenade launcher mounted on a firearm barrel and shows the firing tube in battery position and the tiring pin released to strike the grenade round primer;

FIG. 2 is a view taken along line 2-2 of FIG.

FIG. 3 is a view taken along line 3-3 of FIG.

FIG. 4 is a View taken along line 4-4 of FIG.

FIG. 5 is a view taken along line 5-5 of FIG.

FIG. 6 is a view taken along line `6-6 of FIG.

FIG. 7 is a view taken along line 7-7 of FIG. 3;

FIG. 8 is a fragmentary view of the firing pin, as shown in FIG. 7, but showing the firing pin actuated from the striking position by discharge gas pressure;

FIG. 9 is a fragmentary view similar to FIG. 3 but showing the firing pin held retracted by the secondary Sear and the firing tube held vlforwardly in the loading position;

FIG. 10 is a fragmentary view similar to FIG. 9 but showing the ring tube in battery position and the firing pin in the cocked position;

FIG. 11 is a view taken along line 114-11 of FIG. 9;

FIG. 12 is a view taken along line 12-12 of FIG. 9;

FIG. 13 is a reduced, exploded and perspective view of the launcher; and

FIG. 14 is a View taken along line 14--14 of FIG. 7.

Shown in the figures is a launcher 12 for a round 14 including a grenade 16 with a rotating band 18 and a propellant inclosing case with an extractor groove 22 and such launcher is attachable to a firearm barrel 23. Launcher 12 includes a receiver 24 which is essentially tubular in configuration and is provided with a longitudinal bore 26 which slidingly receives a firing tube 28 so as to be reciprocal therein between a forward overtravel position, past a round loading position, and a rearward battery position. The distance between the loading and battery ipositions is substantially the same as the overall length of round 14. Firing tube 28 is rilied, as noted at 30, so as to engrave rotating band 18, when grenade 116 is discharged down the ring tube, and additional short sections of ritiing, noted at 32, are provided to increase the energy frictionally transferred from the 3,404,479 Patented Oct. 8, 1968 ACC grnade to the firing tube as the grenade leaves the firing tu C.

A rack 34 having a vertical T-slot 36 therein depends from receiver 24 and is arranged to slidingly hold a plurality of rounds 14 with extractor grooves 22 therein being engaged by the T-slot for guiding the rounds successively into the receiver. Rounds 14 in rack 34 are pressed upwardly therein by a spring-biased follower 37. Rounds 14 enter receiver 24 through an opening 38, and a port 40 through the right side of the receiver permits lateral ejection of fired cases 20 from the receiver as hereinafter described. The rear end of firing tube 28 is clear of opening 38 when the firing tube is in the loading position. A breechblock 42 is located in receiver 24 rearward of opening 38 so as to be contactable by the base of round 14, when moved into the receiver, and thereby provides support for the round when discharged. Breechblock 42 houses a firing mechanism 44, to be further described hereinafter, for discharging round 14.

The wall of receiver 24 is increased in thickness on the left side of the central vertical axis thereof to form a longitudinal rib 46 which projects diagonally clear of the firearm barrel when launcher 12 is mounted thereon. A channel 48 of rectangular cross-section is formed in rib 46 from bore 26 so as to extend along the length of tiring tube 28, and a keyhole slot 50 extends through the length of rib 46 to the left and below channel 48 so that the rectangular portion of the keyhole slot provides combmunication between the circular portion thereof and the ore.

Firing tube 28 is provided with an external lug 52 having a cross-section similar to that of keyhole slot 50 so that the lug is matingly received thereby and is movable therealong as the tiring tube reciprocates between the overtravel and battery positions. A compressible coil spring 54 is installed in the circular portion of keyhole slot 50 so that one end bears against lug 52 and the opposite end bears against a plug (not shown) in the end of the keyhole slot for biasing firing tube 28 to battery position.

A. pad 5-6 is fixed to the outside of tiring tube 28 and is matingly received by channel 48 for sliding displacement therein. Pad 56 is positioned slightly forward of a gas port 58 located in tiring tube 28 so as to provide communication between the inside thereof and channel 48 and to be positioned slightly forward of the front end of case 20 in the firing tube when the firing tube is in battery position. Pad 56 is also arranged to contact a buffer device `60 at the front end of rib 46 for resiliently stopping firing tube 28 in the overtravel position and to form the front end of a gas chamber 62 formed in channel 48 as hereinafter explained.

A cooking lever 64 is mounted on the front end of firing tube 28 to provide means for manually actuating the firing tube from the battery to the overtravel position. Firing tube 28 is actuated to the overtravel position during operation of launcher 12 through the frictional engagement of rotating band 18 with rifling 30 as grenade 16 is propelled down the firing tube by discharge forces so that energy is frictionally transferred from the grenade thereto. The short sections of rifling 32 assure that sufticient energy is transferred to firing tube 28 to be actuated to the overtravel position.

An extractor 66 is mounted in the right side of breechblock 42 coincident with the central horizontal plane thereof and is provided with a lip 67 which extends inwardly so as to be receivable by extractor groove 22 of round 14 when moved into receiver 24. Thus, extractor 66 serves to hold round 14 against displacement for discharge and to hold fired case 20 back when firing tube 28 is actuated forwardly to the overtravel position.

Fired ease 20 is ejected out of port 40 by an ejector 68 which, as can best be seen by FIGS. 6 and 13, consists of a rod 70 which is slidingly mounted in a slot 72 formed in bore 26 of receiver 24 diametrically opposite extractor 66. The rear end of ejector 68 is accommodated in a mating recess 79 in breechblock 42 when the ejector is in the rearward position thereof. A rear wall 76 of recess 79 limits the rearward displacement of ejector 68, and a tang 78 extends inwardly from the rear end of rod 70 to be positioned immediately rearward of the base of round 14 when in receiver 24 so as to be actuatable against the base when ejector 68 is forwardly displaced. Ejector 68 is actuated forwardly by the engagement of a projection 80 on tiring tube 28 with front end 82 of a clearance 86 which is formed in rod 70 for the sliding displacement of the projection. Front end 82 is located so as to be contacted by projection 80, when firing tube 28 is between the loading and overtravel positions, and so that, when the firing tube reaches the overtravel position, ejector 68 will be displaced forward suiiiciently to actuate tang 78 against the base of lired case 20 and thereby spin the iired case around extractor lip 67 and out of port 40. Ejector 68 is biased rearwardly into contact with Wall 76 by a spring 88. Clearance 86 is terminated rearwardly by a rear end 84 which is located so that, when liring tube 28 is in the battery position, projection 80 contacts such rear end to hold ejector 68 in its rearward position during movement of the succeeding round 14 into receiver 24 as hereinafter described.

Firing tube 28 is releasably held in the loading position thereof through the engagement of a barrel lock 90, pivotally mounted in breechblock 42, with the rear end of a firing tube extension 92 which is fixed to the outside surface of firing tube 28 so that the front end abuts pad 56 and the rear portion extends past the rear end of the firing tube. During displacement of firing tube 28 from the overtravel to the loading position, the firing tube is moved suiiiciently t permit the displacement of ejector 68 by spring 88 to the rearward position thereof. Thereby, ejector 68 is out of the way and will not interfere with the succeeding round 14 which is pressed into receiver 24 by follower 37 to replace iired case 20. Firing tube extension 92 is slidingly received by channel 48 at the mouth thereof to leave a space between the top of the firing tube extension and the top of channel 48 and thereby complete gas chamber 62. Firing tube extension 92 is slidingly supported in channel 48 through the cooperation of flanges 91 which extend from the sides of the firing tube extension for sliding engagement with mating grooves 93 in the sides of the channel.

Barrel lock 90 is of flat configuration and is located in a transversal slot 94 formed in breechblock 42 so as to be spaced slightly rearward of the front end thereof. A longitudinal pin 96 provides pivotal `support for barrel lock 90 between the right and left ends thereof. The left end of barrel lock 90, as best seen in FIGS. 4 and 11, is provided with a stop 98 which projects upwardly therefrom so as to be positioned in back of the rear end of firing tube extension 92, when the barrel lock is in a locking position, to block rearward displacement as hereinbefore described. When barrel lock 90y is pivoted to an unlock position, stop 98 is displaced clear of tiring tube extension 92 whereby ring tube 28 is to proceed to battery position through the bias of spring 54.

The right end of barrel lock 90, as is best seen in FIG. 1, is provided with an ear 100 which is bent forwardly at right angles therefrom and which is extendable forwardly from the front end of breechblock 42 so as to be contactable by round 14 to pivot the barrel lock to the unlock position when the round is moved into receiver 24 from rack 34. A spring 102 is accommodated in a suitable hole 103 in breechblock 42 so as to press against the bottom of the left end of barrel lock 90 for biasing the barrel lock to the locking position. When barrel lock 90 is in the unlock position, ear 100 is received by a mating recess 104 in receiver 24. Thus, when fired case 20 is ejected from receiver 24, barrel lock 90` is released 4 ,Y n.: "le F and is pressed by spring 102 to move stopy 98 into contact with the bottom surface of firingtube extension 92. When firing tube 28 is adjacent theloading position, barrel lock is freed from firing tube extension 92, permitting the barrel lock to be pivoted by spring 102 the rest of the way to the lock position to block the firing tube in the loading position when returning from the yovertravel position thereof. When succeeding round 14 in rack'34 is moved into receiver 24, ear is contacted by the incoming round to actuate barrel lock, 90 to the unlock position. Thus, tiring tube 28 is released for displacement to the battery position and thereby inclose round 14 which is in receiver 24.

Firing mechanism 44 for discharging the firing tube i-nclosed round 14 consists of a `tiring pin 106 and a triggerdevice 108. Firing pin 106 includes a striker 110 which is actuatable against primer 112 in round 14 for discharge thereof `and such striker is connected to a piston 114 by an arm 116 so that the striker piston and arm form one integral unit. Suitable clearances are provided in breechblock 42 to permit longitudinal displacement of tiring pin 106 between a forward striking 'position and a rearward retracted position.

Piston 114 is rectangular in cross-section and is slidingly received by channel 48 with the front end extending into gas chamber 62. Arm `116 is joined to the bottom of piston 114 at the right side thereof so that the right side of the arm is flush with the right side of the piston and the left side of the a-rm joins the bottom of the piston in the right half section thereof as best seen in FIG. 3. Firing tube extension 92 is provided with a cutout portion 118 on the right side thereof to provide clearance for relative movement of the tiring tube extension and arm 116. When firing pin -106 is in the striking position, the front end of piston 114 is rearwardly adjacent gas port 58.

Firing pin 106 is biased forwardly to the striking position by a spring 120 `which is positioned in channel 48 between the rear end of piston 114 and a cup -122 which is t-hreadingly mounted onv the rear end of receiver 24. Spring 120 is supported by a pin 124 which is in turn supported at the rear end by cup v122 and is slidingly received at the front end by a mating bore 126 in piston 114. Firing pin l106 is actuated rearwardly by gases which result from the discharge of round 14 in receiver 24 and which are bled therefrom through gas port 58 into gas chamber `62 to act against the front end of piston 114. A buifer 128 extends forwardly from cup .122 to resiliently stop firing pin 106 in t-he retracted position.

Firing pin 106 may be retracted manually lby a charging device 130 which consists of a slide 132 of inverted U-shape configuration and a handle 134 extending outwardly therefrom. Slide 132 is slidingly received by channel 48 with handle 134 extending outwardly-'therefrom through a slot `136 in the top thereof and such slide is received by a vertical slot 138 in arm 116 to permit relative movement between the slide and piston. Slot 138 is terminated vat the front end of a front wall 140 and at the rear end by a rear wall 142. Walls 140 and 142 are longitudinally spaced sufficiently to permit relative displacement of charging device 130 and firing pin 106 a distance which is slightly less than the distance traveled by firing pin 106 between the firing land retracted positions thereof. 4 v

Rearward pressure' applied by slide' 132 to rear `|wall 142, as charging device 130 is manually pulled rearwardly, actuates `firing pin 106 to the cocked lposition and rearward pressure by front wall 140 to the front end of the slide, when the `firing is past the cocked position, displaces the charging device rearwardly for a purpose to be hereinafter explained.

Firing tube 28 is releasably looked in the battery position through the cooperation of charging device 130 with a roller -144 which is slidingly received in a pair of laterally related slots v146 through-the sides of channel 48.

Slots 146 are elongated to permit sliding displacement of roller 144 normal to the lateral planes of firing tube extension 92 and charging device 130. Roller 144 is partially receivable by a recess 148 in the top of ring tube extension 92 when firing tube 28 is in battery position. Recess `148 is terminated at the rear end by an arcuate ramp 150 which displaces roller -144 upwardly in slots `146 when [tiring tube extension 92 is displaced forwardly from battery position.

A longitudinal recess 152 is formed in the bottom of piston 114 rearwardly of the front end thereof to provide clearance for roller .144 during movement of the piston relative thereto. Recess 152 forms top surfaces 154 which are parallel to the path of movement of piston 114 and arearranged to pass over roller 144 during displacement of tiring pin 106 to the striking position to hold the roller in recess 148 and thereby lock tiring tube 28 in battery position. The depth of recess 152 is increased sufficiently at the front section as noted at 156, so that, when such increased section is in registry with roller 144, the additional clearance is sufficient to permit displacement of roller 144 from recess 148 and so release firing tube 28 for forward displacement. Section 156 is arranged to be in registry with roller 144 when firing pin 106 is adjacent the striking position thereof. An arcuate notch 158, having the same radius as roller 144, is formed in the bottom front corner of slide 132 and is arranged to receive the roller when charging device 130 is pushed forwardly by contact of rear wall 142 therewith when firing pin 106 is adjacent the firing position thereof. Thus, charging device 130 retains roller 144 in recess 148 to block forward displacement of tiring tube 28 from the battery position until front wall 140 of slot .138 in piston 114 contacts the front end of slide 132, during rearward movement of firing pin 106 when the firing pin is past the cocked position thereof, to knock the charging device clear of the roller. Thus, the upward thrust of roller 144, caused by the camming engagement of the roller by ramp 150 through the frictional force applied by grenade 16 to tiring .tube 28, is borne by charging device 130 and does not press against piston 114 and cause a drag thereon during actuation by the discharge gas forces to the retracted position.

Trigger device 108 is essentially the same as that disclosed in another patent application of mine for Semiautomatic Grenade Launcher, Ser. No. 112,125, iled May 23, 1961, and includes a trigger 160 with a secondary sear 162 which is resiliently mounted in the trigger and is arranged to releasably latch onto tiring pin 106 when actuated to the retracted position and the trigger is pressed inwardly to the firing position. A primary sear 164 is integrally formed on trigger 160 and is arranged to releasingly latch onto firing pin 106 for retention thereof in the cocked position after the trigger is released and secondary sear .162 is actuated thereby to release the tiring pin. A safety 166 must be pressed inwardly before trigger 160 can `be actuated to the tiring position or the sear and trigger can be simultaneously pressed together.

Operation When launcher 12 is ready -to be fired, tiring tube 28 is in battery position, inclosing la round 14, and tiring pin 106 is releasably held cocked by trigger device 108. In- Ward pressure on trigger 160, `after safety 166 is pressed inwardly, moves primary Sear 164 out of engagement with firing pin 106 which is propelled to the tiring position thereof` to discharge round 14 in firing tube 28.

The discharge of round 14 causes grenade 16 to leave case 20, which is retained by extractor 66, and pass along rin-g tube 28. When the rear end of grenade 16 passes gas port 58, gases from the discharge are forced therethrough into gas chamber 62 to act against the front end of piston 114. Responsive to the gas pressure -acting against piston 114, tiring pin 106 is energized rearwardly to the retracted position where it is resiliently stopped by buffer 128 :and engaged by secondary sear 162.

When firing pin 106 passes the cocked position thereof, charging device 130 is knocked free of roller 144 by piston 114 so that the roller is freed -to be cammed upwardly in slots 146 by ramp 150 responsive to the forward pressure being applied to ring tube 28 by grenade 16 yas rotating band 18 therein is engraved by rifling 30 during passage along -the firing tube. When roller 144 is cammed upwardly in slots 146 `and is received by sections 156 of recess 152, it is free of recess 148 and thereby firing tube 28 is unlocked for forward actuation to Ithe overtravel position responsive to the energy transferred there-to by grenade 16. The additional short sections of rifiing 32 at the front end of firing tube 28 Aassure that suficient energy is transferred to firing tube 28 to move the firing tube to the overtravel position and actuate ejector 68.

When firing tube 28 during forward displacement is adjacent loading position, projection thereon contacts front end 82 of clearance 86 in ejector 68, whereby ejector 68 is :actuated forwardly moving tang 78 against the base of fired case 20 which is pivoted around extractor 66 and ejected out of receiver 24 through port 40. In the meantime, tiring tube 28 has rebounded from the overtravel position thereof and is stopped in the loading position by barrel lock which, with the removal of fired case 20, was freed to be pivoted to the locking position.

With the ejection of fired case 20 from receiver 24, subsequent round 14 in rack 34 is freed to be moved into the receiver by follower 37. When such round 14 is fully positioned in receiver 24, ear on barrel lock 90 is contacted by the round to pivotally displace the barrel lock to the unlock position 4and thereby free firing tube 28 which is biased to the battery position to inclose the round. When firing tube 28 reaches battery position, recess 148 comes into registry with roller 144 which is received thereby ready to lock the tiring tube in the battery position when the succeeding round 14 is discharged. When trigger is released, firing pin 106 goes forwardly to be engaged by primary sear 164 Iand ready to discharge the succeeding round 14 when the trigger is pressed inwardly.

From the foregoing it is clearly apparent that there is provided herein a launcher which is ideally suited for the semiautomatic launching -of grenades which are contained in rounds `having Ia low vel-ocity propellant. Such launcher is simple 4in construction, positive in operation and easily manufactured.

Although a particular embodiment of -the invention has been described in detail herein, it is evident that many variations may be devised within the spirit and scope thereof and the following claims :are intended to include such variations.

I claim:

1. A launcher attachable to a rearm bar-rel for successively and semiautomatically discharging a plurality of rounds each including fa grenade and a propellant inclosing case, the launcher including a tiring tube disposed for reciprocation between a forward round loading position and a rearward battery position wherein the loaded one of said rounds is inclosed by said tiring tube for discharge, a spring for biasing said tiring tube from the loading to the battery position, rifling formed in said tiring tube, ra rotating band formed on each of said grenades so as to be engraved by said rifling during passage of said grenade upon discharge from the case 4along said ring tube to frictionally transfer energy from the discharged grenade to said firing -tube for actuation thereof to the loading position, land additional short sections of rifling provided at the muzzle end of said firing tube to -increase the energy frictionally transferred to said tiring tube.

2. A launcher attachable to a firearm barrel for successive-ly and semiautomatically discharging a plurality of rounds each including a grenade and 4-a propellant inclosing case, 'the launcher including a tiring tube disposed for reciprocation between a forward round loading position :and a rearward battery position wherein the loaded one of the rounds is inclosed for discharge, Ia firing pin, means for directing gases from the discharge of each of said rounds 'against said firing pin for actuation thereof to` a cocked position, and means operationally disposed between said firing pin and said firing tube for releasably locking said firing tube in the battery position during actuation of said firing pin to the cocked position.

3. The launcher as defined in claim 2 and including means for actuating said firing tube locking means to release said firing tube during overtravel of said firing pin past the cocked position.

`4. A launcher attachable to a firearm barrel for successively and semiautomatically discharging a plurality of rounds each including a grenade and a propellant inclosing case, the launcher including a firing tube disposed for reciprocation responsive to the passage of the grenade therealong for ejecting the fired case and receiving a subsequent round for discharge in said firing tube, a firing pin, and means for directing gases from the discharge of each of the rounds against said firing pin for actuation thereof to a retracted position.

5. The launcher as dened in claim 4 and including means operationally disposed between said firing tube and said firing pin for releasably locking said firing tube in a battery position wherein the round received by said firing tube is inclosed therein `for discharge.

6. The launcher as defined in claim 4 wherein said firing tube is provided with rifling and the grenade is provided with a rotating band engraved by said rifling during passage of the grenade along said firing tube, and said firing tube is actuated forwardly to a cartridge loading position by the energy frictionally transferred from the grenade to said firing tube by the engraving, and wherein additional short sections of rifiing are provided at the front end of said firing tube to increase the energy frictionally transferred from said grenade to said firing tube.

7. A launcher attachable to a firearm barrel for successively and semiautomatically discharging a plurality of rounds each including a grenade and a propellant inclosing case, the launcher including a receiver mountable to the riflle barrel, a rack depending from said receiver for holding a plurality of the rounds and directing the rounds therein successively into said receiver through an opening therein, a firing tube mounted in said receiver for reciprocation between an overtravel position forward of a loading position wherein said opening is cleared by said firing tube for passage of a round therethrough into said receiver and a battery position wherein the round in said receiver is inclosed by said firing tube for discharge, rifiing in said firing tube, a rotating band disposed on the grenade so as to be engraved by said rifling during passage thereof along said firing tube and frictionally transfer energy from the grenade to the tiring tube for actuating said firing tube to the overtravel position, additional short sections of riing provided in said firing tube at the front end thereof to increase the energy frictionally transferred from the `grenade to the firing tube, and an ejector slidingly :mounted in said receiver for actuation by said firing tube during displacement thereof from the loading to the overtravel position to eject the fired case through a port in said receiver.

y8. The launcher as defined in claim 7 and including a barrel lock held in an unlock position by said round when positioned in said receiver for inclosure by said firing tube and released to a locking position upon ejection of the fired case for stopping said firing tube in the loading position.

9. The launcher as defined in claim 7 and including an extractor mounted in said receiver so as -to be engageable with an extractor groove in the case when moved from said rack into said receiver so as to retainthe respective round therein for discharge and to ihold the case after discharge against displacement respective to said receiver during subsequent displacement of said firing tube to the overtravel position.

10. 'Ehe launcher yas defined in claim 7 and including a firing pin reciprocably mounted in said receiver, and means for directing discharge gases from said firing tube against said firing pin for actuation thereof to a retracted position rearward of a cocked position. Y

11. The launcher as defined in claim 10 and including means operationally disposed between said firing pin and said firing tube for releasably locking said firing tube in the battery position, and means for actuating said firing tube locking means during displacement of said firing pin from the cocked to the retracted position to release said firing tube vfor forward displacement by the energy transyferred thereto from the grenade.

12. A launc-her for semiautomatically discharging grenade rounds each including a grenade and a case, the launcher including a receiver attachable to a firearm barrel, a rack depending from said receiver and adapted to slidingly Iholding a plurality of rounds and for delivering the Irounds successively into said receiver through `an opening therein, a firing tube mounted in said receiver for sliding reciprocation between an overtravel position forward of a loading position wherein the rear end of said firing tube is clear of said opening to permit the passage of a round therethrough into said receiver and a battery position wherein the receiver positioned round is inclosed by said firing tube for discharge, a longitudinal channel formed in said receiver from the inside thereof, an extension fixed to the outside of said firing tube so as to extend from a pad thereon rearwardly of the rear end of said firing tube, said extension and said pad being adapted to be slidingly received by said channel to form a gas cylinder therein, a gas port extending from inside said firing tube to said gas chamber for bleeding discharge gases thereinto, a breechblock for supporting the rear end of the round -for discharge, a firing pin slidingly mounted in said breechblock for reciprocation between a striking position and a retracted position rearward of a cocked position, said firing pin including a piston slidingly received by said channel so as to be acted against by the discharge gases in said gas cylinder for actuating said firing pin to the retracted position, means operationally disposed between said extension and said piston for releasably locking said firing tube in the battery position during displacement of said firing pin from the cocked to the striking position, means for releasing said firing tube locking means to unlock said firing tube when said firing pin is actuated rearwardly from the cocked to the retracted position thereof, an ejector slidingly mounted in said receiver for actuation by said firing tube when displaced from the loading to the overtravel position thereof -for ejecting the fired case through a port in said receiver, a barrel lock pivotally mounted in said breechblock so as to be engageable with the rear end of said extension for holding said firing tube in the loading position after the ejection of the fired case from said receiver and so as to release said firing tube for rearward displacement to the battery position when a succeeding round is moved into said receiver for inclosure by said ring tube during displacement to the battery position, and means for transferring sufficient energy from the grenade to said firing tube for actuation thereof to the overtravel position.

13. The launcher as defined in claim 12 wherein said means for transferring the energy from the -grenade to said firing tube includes riing formed therein for engraving a rotating band on the grenade, and additional short sections of rifling provided at the muzzle end of said firing tube.

14. The launcher as defined in claim 12 wherein said means ifor releasably locking said firing tube in the battery position includes a roller slidingly mounted in elongated slots provided in the portion of said receiver forming said channel and arranged so that the longest taxis thereof is normal to the path of reciprocation of said extension, a reces-s disposed in said extension for partially receiving said roller when said tiring tube is in the battery position, an arcuate ramp terminating the rear end of said recess whereby contact of said ramp with said roller when held in said recess holds said firing tube in the battery position and said roller is cammed by said ramp from said recess for unlocking said liring tube when said roller is freed for upward displacement, a charging device slidingly mounted in said channel contiguous to said piston and said extension for relative movement respective thereto, and notches disposed in said charging device for holding said roller in said recess when said roller is received by said notches.

15. The launcher as defined in claim 14 wherein said means for releasing said tiring tube locking means includ'es'a slot disposed in said piston fori'slidingly Ireceiving said charging device for relative displacement therebetween, and a rear end on said slot having contact with said charging device when said firing pin is displaced from the cocked to the retracted position for displacing said charging device suticiently to free said roller from said notches.

References Cited BENJAMIN A. BORCHELT, Primary Examiner. 

1. A LAUNCHER ATTACHABLE TO A FIREARM BARREL FOR SUCCESSIVELY AND SEMIAUTOMATICALLY DISCHARGING A PLURALITY OF ROUNDS EACH INCLUDING A GRENADE AND A PROPELLANT INCLOSING CASE, THE LAUNCHER INCLUDING A FIRING TUBE DISPOSED FOR RECIPROCATION BETWEEN A FORWARD ROUND LOADING POSITION AND A REARWARD BATTERY POSITION WHEREIN THE LOADED ONE OF SAID ROUNDS IS INCLOSED BY SAID FIRING TUBE FOR DISCHARGE, A SPRING FOR BIASING SAID FIRING TUBE FROM THE LOADING TO THE BATTERY POSITION, RIFLING FORMED IN SAID FIRING TUBE, A ROTATING BAND FORMED ON EACH OF SAID GRENADES SO AS TO BE ENGRAVED BY SAID RIFLING DURING PASSAGE OF SAID GRENADE UPON DISCHARGE FROM THE CASE ALONG SAID FIRING TUBE TO FRICTIONALLY TRANSFER ENERGY FROM THE DISCHARGE GRENAGE TO SAID FIRING TUBE FOR ACTUATION THEREOF TO THE LOADING POSITION, AND ADDITIONAL SHORT SECTIONS OF RIFLING PROVIDED AT THE MUZZLE END OF SAID FIRING TUBE TO INCREASE THE ENERGY FRICTIONALLY TRANSFERRED TO SAID FIRING TUBE. 